For some reason, I thought this thread had veered into using images for initial drop caps, which I had posted about in a different thread. I now see that you're referring to inline images for the special characters. I'd thought of that, but it wouldn't take into account the font or size the ereader is using. According to B&N, the Nook has three fonts. I suppose I could embed the three special characters for all three fonts (if I knew what the fonts were), but would the ereader select the correct one for the font being used? Could I code for it? And what would happen if the user changes the font size? Would the images scale with it?

I don't know who said 3, but that's not right. It's 6 Fonts, and the font sets change slightly between our color and e-ink devices.

I'm pretty sure that there isn't a way to select images based upon font styling.